1. Field of the Invention
The present invention relates generally to wireless vehicle tire pressure monitoring and, more particularly, to a system and method for wireless vehicle tire pressure monitoring that provide for automatic recognition of tire location.
2. Background
It is known in the automotive industry to provide for wireless monitoring of vehicle tire parameters, particularly tire pressure. In such tire pressure monitoring systems, tire pressure sensors and radio frequency (RF) transmitters are mounted inside each tire, typically adjacent the inflation valve stem. In each tire, the tire pressure sensed by the tire pressure sensor is transmitted by the transmitter to a receiver/controller located on-board the vehicle. The tire pressure information delivered to the receiver/controller by the RF signals from the transmitters is subsequently conveyed to a vehicle operator or occupant, typically in the form of a display.
Exemplary tire pressure monitoring systems are described and shown in U.S. Pat. Nos. 6,112,587 and 6,034,597. To recognize the particular tire location (e.g., front left (FL), front right (FR), rear left (RL), rear right (RR)) associated with an RF signal received from a tire transmitter, such tire pressure monitoring systems are programmed in an initialization or sign-up operation. That is, in order to provide a vehicle operator with information specific to each vehicle tire, programming of the tire pressure monitoring system must be undertaken by a technician or vehicle owner so that each RF signal from a tire transmitter will be associated with a particular tire location.
Current tire pressure monitoring systems use a magnetic reed switch in each tire for such programming. More particularly, after the on-board vehicle/controller is placed into a program, initialization, or sign-up mode, the magnetic reed switch in each tire is activated by a technician or vehicle owner using a magnet. Such activation causes the tire transmitter in the tire to transmit a tire pressure signal to the controller the vehicle. In that regard, each pressure sensor and/or transmitter has a unique identification code associated therewith, which identification code is transmitted with the tire pressure signal. Using such identification codes, and by following a preselected sequence for activating each magnetic reed switch, the controller associates each tire pressure signal with a particular tire location.
Such operation, however, can create problems when tires are subsequently rotated or changed from their initial locations to new locations, or a vehicle tire is replaced. Each time the vehicle tires are rotated or a tire is replaced, initialization or sign-up must be repeated to ensure that the system continues to operate properly by conveying accurate information, including tire location, to the vehicle operator. This initialization requirement makes tire rotation more complex, and increases the possibility of inaccurate operation of the system. Moreover, in the event the magnet for activating the reed switches is misplaced or lost, the tire pressure monitoring system cannot be properly programmed after tire rotation.
Thus, there exists a need for an improved system and method for identifying tire locations in a tire pressure monitoring system. Such a system and method would automatically recognizes tire location even after tire rotation, without the need for subsequent initialization or sign-up operations. Such a system and method would also do so easily and simply, without adding significant costs to the tire pressure monitoring system.
Accordingly, the present invention provides an improved system and method for vehicle tire pressure monitoring that provide for automatic recognition of tire location.
According to the present invention, then, in a system for remote monitoring of tire pressure in a vehicle having a plurality of tires, each tire having a location, a system is provided for automatically identifying tire location. The system comprises a plurality of tire monitors, each monitor for mounting in one of the plurality of tires, each monitor comprising a sensor for sensing tire pressure, a transmitter for transmitting a signal representative of the sensed tire pressure, and a magnetic switch for actuating the transmitter to transmit a tire pressure signal. The system further comprises a plurality of electromagnets, each electromagnet for mounting on-board the vehicle in proximity to one of the plurality of tire locations for association with one of the plurality of tire monitors, each electromagnet for generating a magnetic field causing the magnetic switch of the associated tire monitor to actuate the transmitter of the associated tire monitor to transmit a tire pressure signal. The system still further comprises a receiver for mounting on-board the vehicle for receiving the tire pressure signals transmitted by the transmitters, and a controller for mounting on-board the vehicle, the controller to be provided in communication with the plurality of electromagnets and the receiver, the controller for processing tire pressure signals received by the receiver and for use in conveying tire pressure and location information to a user. The controller energizes the plurality of electromagnets so that each received tire pressure signal is automatically associated with one of the plurality of tire locations.
Also according to the present invention, in a system for remote monitoring of tire pressure in a vehicle having a plurality of tires, each tire having a location, a method is provided for automatically identifying tire location. The method comprises providing a plurality of tire monitors, each monitor for mounting in one of the plurality of tires, each monitor comprising a sensor for sensing tire pressure, a transmitter for transmitting a signal representative of the sensed tire pressure, and a magnetic switch for actuating the transmitter to transmit a tire pressure signal. The method further comprises providing a plurality of electromagnets, each electromagnet for mounting on-board the vehicle in proximity to one of the plurality of tire locations for association with one of the plurality of tire monitors, each electromagnet for generating a magnetic field causing the magnetic switch of the associated tire monitor to actuate the transmitter of the associated tire monitor to transmit a tire pressure signal. The method still further comprises providing a controller for mounting on-board the vehicle, the controller to be provided in communication with the plurality of electromagnets, the controller for processing tire pressure signals received from the transmitters for use in conveying tire pressure and location information to a user. The controller energizes the plurality of electromagnets so that each received tire pressure signal is automatically associated with one of the plurality of tire locations.